The core network of wireless evolution network mainly includes logic functional entities, such as mobility management entity (MME), serving system architecture evolution (SAE) gateway (S-GW), and packet data network (PDN) SAE gateway (P-GW). The MME is in charge of non-access stratum (NAS) signaling as well as the encryption, roaming, and tracking of the NAS signaling, the allocation of temporary user identities, and security functions, and is corresponding to a control plane of a serving GPRS support node (SGSN) in the existing Universal Mobile Telecommunications System (UMTS). The S-GW is in charge of local mobility anchor points and mobility anchor points in a 3GPP system as well as lawful interception of related information. The P-GW is in charge of policy enforcement and charging as well as lawful interception of related functions. The home subscriber server (HSS) is adapted to store user subscription information.
Currently, a double registration mechanism is widely applied in the art. According to the mechanism, in order to reduce the interaction of the MME and the HSS caused by the switching of user equipment (UE) between different radio access types (RATs), it is regulated that when the UE is switched between different RATs, the MME and the SGSN are both registered with the HSS, and the HSS saves information about the SGSN and the MME at the same time. Thereby, when the UE is switched between different RATs, the interaction of the MME/SGSN and the HSS is reduced, and the message load on the HSS is lowered.
However, the following problem has become apparent in the art.
Under the double registration mechanism, for some source MMEs of certain versions, the HSS may not delete registration information about the source MME after receiving an Update Location message. However, if the source MME is of some other specific versions, the HSS needs to delete registration information about the source MME, and send a message to notify the source MME to cancel its location registration information. Therefore, the HSS can only determine whether it is necessary to delete the information about the source MME after acquiring the version of the source MME. While in the conventional art, the HSS is unable to obtain the version of the MME, and thus fails to determine whether it is necessary to delete the information about the source MME.